Explosion-proof product pressure overlap prediction and evaluation method

Abstract

The invention provides a method for predicting and evaluating pressure overlap of an explosion-proof product. The method comprises the following steps: abstracting an explosion pressure overlap model from the explosion-proof product; acquiring basic data of the explosion state of the explosion-proof product, wherein the basic data comprises initial pressure, initial temperature, gas substance amount and explosion volume before explosion; according to the formula # imgabs0 # and the gas explosion reaction equation, the theoretical maximum pressure value during explosion is calculated in combination with the pressure overlapping model and the basic data. According to the method, after the explosion pressure overlapping model is abstracted from the explosion-proof type product, the corresponding basic data are obtained, the theoretical maximum pressure value during explosion is calculated in combination with the gas explosion reaction equation and the pressure calculation model, and prediction of the maximum pressure value of pressure overlapping and evaluation of the explosion-proof performance of the explosion-proof shell are facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of product explosion protection, and particularly relates to a method for predicting and evaluating pressure overlap of flameproof products. Background Art

[0002] For flameproof products, the change of internal pressure during an explosion is complex. Generally, in the case of a relatively typical explosion cavity of a flameproof product, when the pressure, temperature, and explosive mixture are determined, a theoretical value close to the actual value can be obtained through theoretical calculation. However, in many cases, the internal cavity structure of a flameproof product is not a typical cavity structure but a relatively complex special structure. Once an explosion occurs in this special structure, there will be a "pressure overlap" situation. The definition of "pressure overlap" is: when ignition occurs in a cavity of the flameproof enclosure, the pre-pressed state of the gas mixture in another cavity when it is ignited is called pressure overlap. The pressure accumulation phenomenon caused by pressure overlap is a very important factor affecting the performance of the flameproof enclosure.

[0003] That is, when the explosion source flame propagates, the unburned gas / mixture in front is compressed and burned, and a pressure that is two to eight times the initial pressure can be generated. This pressure overlap has a great impact on the explosion-proof characteristics of flameproof products. Therefore, predicting and evaluating the pressure overlap of flameproof products is of great significance for the design and performance evaluation of flameproof products. Summary of the Invention

[0004] In view of the above technical problems, the present application proposes a method for predicting and evaluating pressure overlap of flameproof products, and the specific technical solutions are as follows:

[0005] A method for predicting and evaluating pressure overlap of flameproof products, the method is as follows:

[0006] Abstract an explosion pressure overlap model from the flameproof product;

[0007] Obtain the basic data of the explosion state of the flameproof product, and the basic data includes the initial pressure, initial temperature, amount of gas substance, and explosion volume before the explosion;

[0008] According to Equation (1) and the gas explosion reaction equation, combine the pressure overlap model and the basic data to calculate the theoretical maximum pressure value during the explosion;

[0009]

[0010] In Equation (1), P, T, and n are respectively the maximum pressure, highest temperature, and amount of gas substance after the explosion; P0, T0, and m are respectively the initial pressure, initial temperature, and amount of gas substance before the explosion.

[0011] When implementing this solution, the explosion pressure overlap model includes a small-hole partition model, a finite-space partition model, and a long and narrow pipeline model.

[0012] In the basic data, the initial pressure, initial temperature, and amount of gas substance before explosion are preset values.

[0013] More specifically, when calculating the theoretical maximum pressure value during explosion, the detonation area and pressure overlap area are divided according to the explosion pressure overlap model, the intermediate pressure and intermediate temperature after the explosion in the detonation area are calculated, and used as the initial pressure and initial temperature in the pressure overlap area, and the theoretical maximum pressure value in the pressure overlap area is calculated.

[0014] When implementing this solution, the ratio of the small-hole diameter to the partition diameter in the small-hole partition model does not exceed 1:20.

[0015] When implementing this solution, in the finite-space partition model, the area of the partition accounts for 60% - 80% of the cross-sectional area of the outer shell, and the partition is placed at 2 / 3 of the main axis and parallel to the secondary axis.

[0016] When implementing this solution, in the long and narrow pipeline model, the pipeline length: diameter > 10:1.

[0017] The beneficial effects of the present invention are as follows: After abstracting the explosion pressure overlap model from the explosion of explosion-proof products, and obtaining the corresponding basic data, combined with the gas explosion reaction equation and pressure calculation model, the theoretical maximum pressure value during explosion is calculated, which is beneficial to predicting the maximum pressure value of pressure overlap and evaluating the explosion-proof performance of the explosion-proof shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shows the small-hole partition model;

[0019] Figure 2 Shows the finite-space partition model;

[0020] Figure 3 Shows the long and narrow pipeline model;

[0021] Figure 4 Shows the measured model of Example 1;

[0022] Figure 5 Shows the explosion test system of Example 1;

[0023] Figure 6 Shows the hydrogen pressure overlap curve of Example 1;

[0024] Figure 7 Shows the ethylene pressure overlap curve of Example 1;

[0025] Figure 8Shown is the measured model of Example 2;

[0026] Figure 9 Shown is the hydrogen pressure overlap curve of Example 2;

[0027] Figure 10 Shown is the ethylene pressure overlap curve of Example 2;

[0028] Figure 11 Shown is the acetylene pressure overlap curve of Example 2;

[0029] Figure 12 Shown is the measured model of Example 3;

[0030] Figure 13 Shown is the hydrogen pressure overlap curve of Example 3;

[0031] Figure 14 Shown is the ethylene pressure overlap curve of Example 3;

[0032] Figure 15 Shown is the acetylene pressure overlap curve of Example 3;

[0033] Figure 16 Shown is the measured model of Example 4;

[0034] Figure 17 Shown is the hydrogen pressure overlap curve of Example 4;

[0035] Figure 18 Shown is the acetylene pressure overlap curve of Example 4;

[0036] Figure 19 Shown is the measured model of Example 5. Detailed implementation manners

[0037] In the following description, certain specific details are set forth in order to provide a thorough understanding of the various embodiments. However, those skilled in the art will understand that the present invention may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. Unless the context otherwise requires, throughout the specification and the appended claims, the word "comprising" shall be interpreted in an open, inclusive sense, i.e., as "including, but not limited to".

[0038] For the "pressure overlap" situation that occurs when an explosion-proof product explodes, to evaluate the maximum pressure data of the explosion, it is first necessary to abstract an explosion pressure overlap model based on the actual explosion-proof product, then determine the basic data in the explosion state based on the actual explosion-proof product, and then calculate the theoretical maximum pressure value during the explosion in combination with the pressure overlap model and the basic data.

[0039] The explosion pressure overlap models that can be obtained through abstraction include the small-hole partition model, the finite-space partition model, and the long and narrow pipeline model. More specifically, the above three models have the following characteristics respectively:

[0040] (1) Figure 1 The small-hole partition model is shown. In this model, there are cavity 1, cavity 2, and a partition. There are small holes on the partition, such that cavity 1 and cavity 2 are only connected to each other through the small holes, and the volumes of cavity 1 and cavity 2 are not the main limiting factors;

[0041] When an explosion occurs in cavity 1, the speed of the explosion flame is slow (about 3.39 m / s), but the propagation speed of the pressure wave is faster (about 330 m / s). Therefore, the pressure in cavity 1 is first transmitted to cavity 2, causing the pressure of the explosive mixture in cavity 2 to increase. Then the flame is transmitted to cavity 2, causing the compressed gas in cavity 2 to explode. At this time, the pressure generated in cavity 2 is several times, or even dozens of times, the original pressure.

[0042] In the small-hole partition model, the small holes on the partition can form an explosion pressure overlap model only under specific conditions, and the diameter of the small holes to the diameter of the partition is 1:20 or less.

[0043] (2) Figure 2 The finite-space partition model is shown. In this model, the partition is set in a finite space. The finite space forms a structure similar to cavity 1 and cavity 2 through the partition, and the cavity volume of the finite space is the main limiting factor.

[0044] When an explosion occurs in cavity 1 on one side of the partition, the pressure in cavity 1 is first transmitted to cavity 2, causing the pressure of the explosive mixture in cavity 2 to increase. Then the flame is transmitted to cavity 2, causing the compressed gas in cavity 2 to explode. At this time, the pressure generated in cavity 2 is several times, or even dozens of times, the original pressure.

[0045] In the finite-space partition model, the so-called finite space only refers to the space inside the explosion-proof shell, and the size of the space is determined by the explosion-proof shell. The volume of the finite space is not limited. The specific conditions for forming an explosion pressure overlap model are: the area of the partition accounts for 60% - 80% of the cross-sectional area of the outer shell, and the partition is placed at 2 / 3 of the main axis and parallel to the secondary axis.

[0046] (3) Figure 3 The long and narrow pipeline model is shown. This model does not have typical small holes or partitions. It is itself a relatively common pipeline. It is only that when the length of the pipeline exceeds a certain value, when an explosion occurs inside it, a typical "pressure overlap" situation will also occur.

[0047] When an explosion occurs at end A of the pipeline, the pressure at end A is first transmitted to end B, increasing the pressure of the explosive mixture at end B. Then, the flame is transmitted to end B, causing the compressed gas at end B to explode. At this time, the pressure generated at end B is several times, or even dozens of times, the original pressure.

[0048] In the long and narrow pipeline model, an explosion pressure overlap model can only be formed when the pipeline parameters are under specific conditions, and the pipeline length: diameter > 10:1.

[0049] In this application, the basic data for determining the explosion state based on actual flameproof products includes the components of the combustible mixture, initial pressure, initial temperature, and concentration. However, in actual applications, the relevant data of the explosion state are unpredictable. Therefore, usually, these data are set according to relevant test standards or equivalently set to the test standards. That is, "pressure overlap" prediction is carried out under relevant test standards, and the prediction results under this condition can be used as the relevant basis for product design or performance evaluation. Specifically, in this application, the set volume fraction of the explosion mixture is any one of 31 ± 1% hydrogen (electrical equipment of Class IIC), 14 ± 1% acetylene (electrical equipment of Class IIC), and 8 ± 0.5% ethylene (electrical equipment of Class IIB), the initial pressure is 0.1 MPa, and the initial temperature is 293.15 K.

[0050] Unless otherwise specified, the explosion mixture is a mixture of explosive gas and air.

[0051] The maximum explosion pressure generated during an explosion can be determined according to the relationship that pressure is directly proportional to the thermodynamic temperature and the number of moles. Based on this relationship, the following formula can be obtained:

[0052]

[0053] In the formula: P, T, and n are the maximum pressure (MPa), highest temperature (K), and amount of gas substance (mol) after the explosion, respectively; P0, T0, and m are the initial pressure (MPa), initial temperature (K), and amount of gas substance (mol) before the explosion, respectively.

[0054] By changing the variables on both sides of the equation, the calculation formula for the maximum explosion pressure can be derived:

[0055]

[0056] When calculating the theoretical maximum pressure value during an explosion by combining the pressure overlap model and the basic data, it is necessary to simultaneously combine the explosion reaction formula (1) and the explosion pressure calculation formula (2):

[0057]

[0058] 2H2 + O2 = 2H2O

[0059] C2H4 + 3O2 = 2CO2 + 2H2O

[0060] 2C2H2 + 5O2 = 4CO2 + 2H2O (2)

[0061] In formula (1), P, T, and n are respectively the maximum pressure (MPa) after explosion, the highest temperature (K), and the amount of gas substance (mol). The highest temperature (K) can be obtained by referring to the combustion characteristics of the flammable gas - air mixture; P0, T0, and m are respectively the initial pressure (MPa), the initial temperature (K), and the amount of gas substance (mol) before explosion;

[0062] In formula (2), they are respectively the reaction equations for the explosion of different flammable gases. According to these reaction equations, the relevant amount of gas substance in formula (1) can be calculated.

[0063] According to the definition of "pressure overlap", when ignition occurs in one cavity of the flameproof enclosure and causes the gas mixture in another cavity to be pre - pressed and ignited, this state is called pressure overlap. Therefore, when predicting and calculating the maximum explosion pressure, it is necessary to determine the ignition area and the pressure overlap area in the explosion pressure overlap model.

[0064] Taking the small - hole partition model as an example, if cavity 1 is the ignition area and cavity 2 is the pressure overlap area, then during calculation, first calculate the intermediate pressure and intermediate temperature after the explosion of cavity 1 according to formula (1) and formula (2); then use the intermediate pressure and intermediate temperature after the explosion of cavity 1 as the initial pressure and initial temperature of cavity 2, and perform a secondary calculation based on formula (1) and formula (2) to obtain the maximum explosion pressure.

[0065] Example 1

[0066] As Figure 4 shown, a scenario of "pressure overlap" occurring during explosion provided in this example is specifically set as two sections of pipes A and B, with an orifice plate arranged between pipes A and B. According to the model characteristics, it can be abstracted into a small - hole partition model. The specific data settings in this example are as follows:

[0067] Total cavity volume: 10 L;

[0068] Length of pipe A: 250 mm;

[0069] Length of pipe B: 500 mm;

[0070] Ignition position of the explosion: one end of pipe B;

[0071] Calculate the maximum pressure values under two different explosion conditions of 31 ± 1% hydrogen and 8 ± 0.5% ethylene respectively.

[0072] The combustion temperature T when 31 ± 1% hydrogen burns completely is 1430K;

[0073] The initial pressure of chamber 2 is the pressure P0 of chamber 1 before pressure overlap, P0 = 0.200 MPa;

[0074] The initial temperature is normal temperature 293K;

[0075] The ratio of the amount of gas substance (mol) before and after explosion n / m = 3 / 2;

[0076] Substituting these data into Equation (1), the maximum pressure value of 31 ± 1% hydrogen is calculated to be 1.464 MPa.

[0077] The combustion temperature T when 8 ± 0.5% ethylene burns completely is 2557K;

[0078] The initial pressure of chamber 2 is the pressure P0 of chamber 1 before pressure overlap, P0 = 0.251 MPa;

[0079] The initial temperature is normal temperature 293K;

[0080] The ratio of the amount of gas substance (mol) before and after explosion n / m = 4 / 4;

[0081] Substituting these data into Equation (1), the maximum pressure value of 31 ± 1% hydrogen is calculated to be 1.447 MPa.

[0082] Correspondingly, in this embodiment, an actual explosion test was also carried out simultaneously. Specifically, the Figure 5 explosion test system shown in was used. The pressure measurement position was one end of pipeline A. The calculation and test data are shown in Table 1 in detail. At the same time, the pressure overlap curve obtained from the test was provided. Figure 6 is the hydrogen pressure overlap curve, Figure 7 is the ethylene pressure overlap curve.

[0083]

[0084] Table 1

[0085] Example 2

[0086] As Figure 8 shown, a scenario of "pressure overlap" during explosion provided in this embodiment is specifically set as a small-volume square box with a large-area partition installed inside. According to the model characteristics, it can be abstracted into a finite-space partition model. The specific data settings in this embodiment are as follows:

[0087] Total cavity volume: 3L;

[0088] Explosion ignition position: the top of the square box;

[0089] Calculate the maximum pressure values under three different explosion conditions of 31±1% hydrogen, 8±0.5% ethylene, and 14±1% acetylene respectively.

[0090] The combustion temperature T when the exemplary 31±1% hydrogen burns completely is 1430K;

[0091] The initial pressure of cavity 2 is the pressure P0 = 0.13MPa of cavity 1 before pressure overlap;

[0092] The initial temperature is the normal temperature of 293K;

[0093] The ratio of the amount of gas substance (mol) before and after explosion n / m = 3 / 2;

[0094] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31±1% hydrogen is 0.952MPa.

[0095] The combustion temperature T when the exemplary 8±0.5% ethylene burns completely is 2557K;

[0096] The initial pressure of cavity 2 is the pressure P0 = 0.119MPa of cavity 1 before pressure overlap;

[0097] The initial temperature is the normal temperature of 293K;

[0098] The ratio of the amount of gas substance (mol) before and after explosion n / m = 4 / 4;

[0099] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31±1% hydrogen is 1.039MPa.

[0100] The combustion temperature T when the exemplary 14±1% acetylene burns completely is 2893K;

[0101] The initial pressure of cavity 2 is the pressure P0 = 0.10MPa of cavity 1 before pressure overlap;

[0102] The initial temperature is the normal temperature of 293K;

[0103] The ratio of the amount of gas substance (mol) before and after explosion n / m = 7 / 6;

[0104] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31±1% hydrogen is 1.152MPa.

[0105] Correspondingly, in this embodiment, an actual explosion test was also carried out simultaneously. The system of the explosion test replaced the pipeline with a square box on the basis of Embodiment 1. The pressure measurement position was the side of the square box. The calculation and test data are shown in Table 2 in detail. At the same time, the pressure overlap curve obtained by the test was provided. Figure 9 It is the hydrogen pressure overlap curve, Figure 10 It is the ethylene pressure overlap curve,Figure 11 It is the acetylene pressure overlap curve.

[0106]

[0107] Table 2

[0108] Example 3

[0109] As Figure 12 shown, it is a scenario of "pressure overlap" occurring during an explosion provided in this example. Specifically, it is set as a long and narrow pipeline, which can be abstracted into a long and narrow pipeline model according to the model characteristics. The specific data settings in this example are:

[0110] Total cavity volume: 2 L;

[0111] Total pipeline length: 0.5 m;

[0112] Ignition position of the explosion: one end of the pipeline (corresponding to the pressure measurement end);

[0113] Calculate the maximum pressure values under three different explosion conditions of 31 ± 1% hydrogen, 8 ± 0.5% ethylene, and 14 ± 1% acetylene respectively.

[0114] Exemplarily, the combustion temperature T = 1430 K when 31 ± 1% hydrogen is completely burned;

[0115] The initial pressure of cavity 2 is the pressure P0 = 0.13 MPa of cavity 1 before pressure overlap;

[0116] The initial temperature is room temperature 293 K;

[0117] The ratio of the amount of gas substance (mol) before and after the explosion n / m = 3 / 2;

[0118] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31 ± 1% hydrogen is 1.592 MPa.

[0119] Exemplarily, the combustion temperature T = 2557 K when 8 ± 0.5% ethylene is completely burned;

[0120] The initial pressure of cavity 2 is the pressure P0 = 0.10 MPa of cavity 1 before pressure overlap;

[0121] The initial temperature is room temperature 293 K;

[0122] The ratio of the amount of gas substance (mol) before and after the explosion n / m = 4 / 4;

[0123] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31 ± 1% hydrogen is 0.873 MPa.

[0124] The combustion temperature T = 2893K when 14±1% acetylene burns completely exemplarily;

[0125] The initial pressure of chamber 2 is the pressure P0 = 0.19MPa of chamber 1 before pressure overlap;

[0126] The initial temperature is normal temperature 293K;

[0127] The ratio of the amount of gas substance (mol) before and after explosion n / m = 7 / 6;

[0128] Substituting these data into Equation (1), the maximum pressure value of 31±1% hydrogen is calculated to be 2.188MPa.

[0129] Correspondingly, in this embodiment, an actual explosion test was also carried out simultaneously. The system of the explosion test replaced the pipeline with a long and narrow pipeline on the basis of Example 1. The pressure measurement position was at the other end of the pipeline. The calculation and test data are shown in Table 3. At the same time, the pressure overlap curve obtained by the test was provided. Figure 13 It is the hydrogen pressure overlap curve, Figure 14 It is the ethylene pressure overlap curve, Figure 15 It is the acetylene pressure overlap curve.

[0130]

[0131] Table 3

[0132] Example 4

[0133] As Figure 16 shown, a scenario of "pressure overlap" occurring during explosion provided in this embodiment is specifically set as a bent pipe, which can be abstracted into a long and narrow pipeline model according to the model characteristics. The specific data settings in this embodiment are:

[0134] Total cavity volume: 2L;

[0135] Total pipeline length: 0.5m;

[0136] Explosion ignition position: one end of the pipeline (corresponding to the pressure measurement end);

[0137] Calculate the maximum pressure values under two different explosion conditions of 31±1% hydrogen and 14±1% acetylene respectively.

[0138] Exemplarily, the combustion temperature T = 1430K when 31±1% hydrogen burns completely;

[0139] The initial pressure of chamber 2 is the pressure P0 = 0.31MPa of chamber 1 before pressure overlap;

[0140] The initial temperature is normal temperature 293K;

[0141] The ratio of the amount (mol) of gaseous substances before and after the explosion is n / m=3 / 2;

[0142] Substituting these data into equation (1), we can calculate that the maximum pressure of 31±1% hydrogen is 2.269 MPa.

[0143] The combustion temperature of the exemplary 14±1% acetylene when it is completely burned is T=2893K;

[0144] The initial pressure is the pressure of cavity 2 before the pressure overlap of cavity 1, P0 = 0.16 MPa;

[0145] The initial temperature is room temperature 293K;

[0146] The ratio of the amount (mol) of gaseous substances before and after the explosion is n / m=7 / 6;

[0147] Substituting these data into equation (1), we can calculate that the maximum pressure of 31±1% hydrogen is 1.843 MPa.

[0148] Accordingly, in this embodiment, an actual explosion test is also carried out. The explosion test system is based on the embodiment 1, except that the pipeline is replaced with an elbow, and the pressure measurement position is the other end of the pipeline. The calculated and tested data are detailed in Table 4, and the pressure overlap curve obtained by the test is also provided. Figure 17 is the hydrogen pressure overlap curve, Figure 18 This is the acetylene pressure overlap curve.

[0149]

[0150] Table 4

[0151] Example 5

[0152] like Figure 19 As shown, a scenario of "pressure overlap" during an explosion provided in this embodiment is specifically set to a flameproof motor. According to the model characteristics, it can be abstracted into a narrow and long pipe model. The specific data in this embodiment is set to:

[0153] Motor center height: 160

[0154] Total cavity volume: about 10L;

[0155] Ignition location of the explosion: front end cover;

[0156] Pressure measuring point location: rear end cover;

[0157] The structure of flameproof motors is relatively complex. Compared with the above-mentioned calculations, the difficulty lies in model abstraction and data correction. It is necessary to first calculate the explosion pressure of chamber 1, test the pressure curve to find the pre-pressure value when chamber 2 is detonated, and then calculate the explosion pressure of chamber 2.

[0158] Calculate the maximum pressure values under two different explosion conditions of 31 ± 1% hydrogen and 14 ± 1% acetylene respectively.

[0159] The combustion temperature T when exemplary 31 ± 1% hydrogen is completely burned is 1430K;

[0160] The initial pressure of chamber 2 is the pressure P0 = 0.13 MPa of chamber 1 before pressure overlap;

[0161] The initial temperature is room temperature 293K;

[0162] The ratio of the amount of gas substance (mol) before and after explosion n / m = 3 / 2;

[0163] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31 ± 1% hydrogen is 0.952 MPa.

[0164] The combustion temperature T when exemplary 14 ± 1% acetylene is completely burned is 2893K;

[0165] The initial pressure of chamber 2 is the pressure P0 = 0.10 MPa of chamber 1 before pressure overlap;

[0166] The initial temperature is room temperature 293K;

[0167] The ratio of the amount of gas substance (mol) before and after explosion n / m = 7 / 6;

[0168] Substitute these data into Equation (1) to calculate that the maximum pressure value of 31 ± 1% hydrogen is 1.152 MPa.

[0169] Correspondingly, in this embodiment, an actual explosion test was also carried out simultaneously. The system of the explosion test replaced the pipeline with an explosion-proof motor on the basis of Embodiment 1. The pressure measurement position was at the other end of the pipeline. The calculation and test data are shown in Table 5. At the same time, the pressure overlap curve obtained by the test was provided. Figure 17 It is the hydrogen pressure overlap curve. Figure 18 It is the acetylene pressure overlap curve.

[0170]

[0171] Table 5

[0172] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. Method for predicting and evaluating pressure overlap of explosion-proof products, characterized in that, The method is as follows: Abstract an explosion pressure overlap model from the flameproof product; Obtain the basic data of the explosion state of the flameproof product, where the basic data includes the initial pressure, initial temperature, amount of gas substance, and explosion volume before explosion; According to Equation (1) and the gas explosion reaction equation, combine the pressure overlap model and the basic data to calculate the theoretical maximum pressure value during explosion; In Equation (1), P, T, and n are respectively the maximum pressure, highest temperature, and amount of gas substance after explosion; P0, T0, and m are respectively the initial pressure, initial temperature, and amount of gas substance before explosion.

2. The pressure overlap prediction and evaluation method for explosion-proof products according to claim 1, characterized in that The explosion pressure overlap model includes a small-hole partition model, a finite-space partition model, and a long and narrow pipeline model.

3. The explosion-proof product pressure overlap prediction and evaluation method according to claim 1, wherein The initial pressure, initial temperature, and amount of gas substance before explosion in the basic data are preset values.

4. The pressure overlap prediction and evaluation method for flameproof products according to claim 1, wherein When calculating the theoretical maximum pressure value during explosion, divide the detonation area and the pressure overlap area according to the explosion pressure overlap model, calculate the intermediate pressure and intermediate temperature after the explosion occurs in the detonation area, and use them as the initial pressure and initial temperature of the pressure overlap area to calculate the theoretical maximum pressure value of the pressure overlap area.

5. The pressure overlap prediction and evaluation method for the flameproof product according to claim 2, wherein In the small-hole partition model, the ratio of the small-hole diameter to the partition diameter does not exceed 1:

20.

6. The method for predicting and evaluating the pressure overlap of the explosion-proof product according to claim 2, wherein In the finite-space partition model, the area of the partition accounts for 60% - 80% of the cross-sectional area of the shell, and the partition is placed at 2 / 3 of the main axis and parallel to the secondary axis.

7. The method for predicting and evaluating the pressure overlap of the explosion-proof product according to claim 2, characterized in that In the long and narrow pipeline model, the pipeline length: diameter > 10:1.

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